Signaling system



Feb. 18, 1936; R R, KEMMERER 2,030,924

SIGNALING SYSTEM Filed April 5, 1935 2 Sheets-Sheet 2 17 To Stick Contact [29 afXS relay at next location.

7 INVENTOR 1209012 12. [femmeren BYMIW HIS ATTORNEY Patented Feb. 18, 1936 SIGNALING SYSTEM Ralph E. Kemmerer, Swissvale, Pa., assignor to The Union Switch & Signal Company, Swissvale, Pa., a corporation of Pennsylvania Application April 5, 1935, Serial No. 14,865

20 Claims.

My invention relates to signaling systems, and particularly to signaling systems for governing the passage of vehicles along a trackway such as, for example, railway trains.

A feature of my invention is the provision of apparatus for a non-contact intermittent control signaling system which is particularly adaptable for use, although in no manner limited thereto, on non-track circuited railways and on railways using vehicles which may not effectively operate track circuits. A further feature of my invention is the provision of apparatus for signaling systems of the intermittent control type wherewith a vehicle or a train of several vehicles is registered into a block of a definite length of the trackway and is again registered as it passes out of such block, and which apparatus is effective to determine the passage of the entire train into the block and to set a signaling device in the position to protect the train before the signaling device of a similar block in the rear of the block 00- cupied is permitted to assume a proceed indication. Still another feature of my invention is the provision of apparatus for intermittent control signaling systems wherewith two different forms of actuators cooperate to differentiate between the front and rear ends of trains. Again, a feature of my invention is the provision of apparatus of the type here involved which is effective to protect movements in and out of a block of the trackway at points other than at the entrance and exit of such block, such as, for example, a siding of a railway track. Other features and advantages of my invention will appear as the specification progresses.

I will describe one form of apparatus embodying my invention, and will then point out the novel features thereof in claims.

For a better understanding of my invention reference may be had to the accompanying drawings in which Figs. la. and 111 when taken together with Fig. 1a placed at the left are a diagrammatic view of one form of trackway apparatus embodying my invention when applied to a railway. Fig. 2 is a diagrammatic view of one form of traincarried apparatus which may be employed for cooperating with the apparatus of Figs. 1a and 1b.

In each of the several views like reference characters designate similar parts.

Although my invention is here disclosed as applied to a railway it is to be understood that I do not limit myself to this one particular application of the invention and other embodiments will suggest themselves to those skilled in the art. This one application of the invention will serve,

however, as an illustration of the many places the invention will be useful.

By referring to Figs. 1a. and lb, I will first describe the trackway apparatus, and then follow that by a description of the train-carried apparatus of Fig. 2. The reference characters II and H designate the traffic rails of a railway along which traffic normally moves in the direction indicated by an arrow andwhich direction for convenience I will term east or eastbound. The trackway is arranged into blocks of any cone venient length by locating wayside signal equipment at each of a plurality of spaced intervals along the trackway. In Figs. 1a and 1b two such signal locations designated by the reference characters I and 3 are shown. It follows that the stretch of trackway between the locations I and 3 forms one block and which is designated as a whole by the reference character Y, the location I being the entrance of the block Y and the location 3 being the exit of that block. The block to the left of block Y is designated as a whole by the reference character X, and the block to the right of the block Y is designated by the reference character Z. Hence, the location I which is the entrance of block Y is the exit of the block X, the entrance of block X not being shown. The location 3 which is the exit of block Y is the entrance of block Z, the exit of block Z not beingshown. In the block Z a track switch 3W leading toa siding track W is located. While in the drawings only one full block, the exit end of a secondblock and the entrance end of a third block are disclosed, it Will be understood that the full length of the railway is arranged in consecutive blocks similar to the blocks X, Y, and Z.

At each signal location, two vehicle controlled actuators for registering a vehicle or train into the block for which that location is the entrance and for subsequently registering the train out of the block for which that location isithe exit are provided. A first one of these actuators I will for convenience refer to as a receiving unit and the second actuator I will refer toas a detecting-unit. These actuators may take different forms and as here shown the receiving unit is an electromagnetic device and the detecting element is a photo-electric device. Each receiving unit includes a wayside receiver, a rectifier and a receiving relay; and each detecting unit includes a light unit, a light responsive unit and a detecting relay.

Referring specifically to location I at,the junction of blocks X and Y, the wayside receiver IR of the receiving unit has its winding I2 connected with the input terminals of a full wave rectifier IRX, the output terminals of which are connected by wires I3 and I4 with the control winding of a receiving relay IZR. This wayside receiver IR may take different forms several of which are well-known and it is deemed sufficient for this application to point out that this receiver is preferably made up of a laminated iron magnetic core in U form, around which the winding I 2 is placed. This receiver is completely enclosed in a non-magnetic casing for mechanical protection and the entire device is secured to the track ties, the core of the receiver being parallel to the trafiic rails outside of the rails and in a position for magnetic relationship with a traincarried inductor to be referred to later. As will appear hereinafter, the train-carried inductor when passing over the wayside receiver IR. is effective to induce an electromotive force in its winding I2. This induced electromotive force when rectified by the rectifier I RX energizes the relay I ZR, which when momentarily picked up is retained in its energized position by virtue of a stick circuit traced from the B terminal of any convenient source of current such as a battery not shown, over back contact I5 of a relay IXR to be, shortly described, wire I6, front contact H of a relay IZR, wires I8 and I4, winding of the relay and wires I3 and I9 to the opposite terminal C of the same source of current. The parts are so arranged that the polarity of the current supplied to the winding of the relay IZR. over this stick circuit is the same as that of the energizing current supplied through the rectifier, and hence relay IZR. once picked up in response to the electromotive force induced in the receiver winding I2 is retained energized over the stick circuit aslong as the back contact I5 of the relay I XR remains closed.

Still referring to location I, a light unit IL of the detecting unit is located on the left-hand side of the track and is arranged to direct a light beam across the track rails as indicated by dotted lines to a light sensitive unit ILC on the righthand side of the track. The light unit IL may take different forms and preferably is an electrically lighted lamp constantly supplied with current from any convenient source over the two lead wires 20 and 2 I, the lamp for the unit IL being enclosed in a suitable weatherproof housing. Preferably the light beam from the unit IL crosses the traffic rails at a distance sufficiently high above the top of the rails so as to pass over the heads of individuals walking along the track but so as to be intercepted by a rail way car. Furthermore, the light unit IL is preferably set to direct its light beams diagonally across the trafiic rails as indicated by the dotted lines, the diagonal arrangement being effective to assure continuous interception of the light beam as long as a car or a train of several cars is passing. If the light beam was directed at right angles across the tramc rails, it might flash between the cars of a train. The light sensitive unit ILC may be of the photo-conductive, photovoltaic, or photo-emissive type, as desired, and is shown conventionally only since its specific structure forms no part of my invention. As here shown, the light sensitive unit ILC is associated with an amplifier IX the output of which includes the control winding of the detecting relay IXR. The arrangement is such that as long as the unit ILC is exposed to the light beam from the unit IL sufficient current is supplied to the relay IXR to effectively energize that relay,

but that when the light beam is intercepted the current supplied to the relay IXR is so reduced the relay is released. It is to be pointed out that while I have referred to the unit IL as a source of light such as an electric lamp and the unit ILC as a light sensitive unit responsive thereto, it will be understood that I do not wish to limit myself to this one arrangement and the unit IL may be a source of so-called quasioptical rays and the respective unit ILC may be a suitable receiver responsive to such rays. The particular value of this latter arrangement is that while it in general performs its function in similar manner to the light sensitive cell, it is immune to the influence of the source of light rays not directly associated with the operation of the system and hence the device is sensitive only to a certain optical characteristic. It is clear that when the head end of a vehicle or train intercepts the light beam the relay IXR is released and subsequently remains down in engagement with its back contacts until the rear end of the train passes beyond the location and the light sensitive unit ILC is again exposed to the light beam. In Fig. la the leading vehicle of a train such as, for example, the locomotive, is indicated at K. Mounted on this vehicle K is an inductor I disposed in a position for magnetic relationship with the wayside receiver IR when the vehicle K passes the location I. scribed hereinafter, the inductor I is adaptable of being energized and a relatively strong magnetic field created thereby. Consequently, as the vehicle K enters the block Y the light beam is intercepted by the body of the vehicle to effect :1.

the release of the detecting relay IXR, and an electromotive force is induced in the wayside receiver IR by the inductor I to effect the energization of the receiving relay IZR. The wayside receiver IR is so positioned with respect to K the light beam and the train-carried inductor I is so positioned with respect to the head end of the vehicle K, that the light beam is intercepted, relay I XR is released and its back contact I5 is closed just prior to the energizing of the relay I ZR in response to the electro-motive force induced in the receiver IR. Hence, the detecting relay IXR is' released and the receiving relay IZR is picked up and held energized by its stick circuit as the head end of a train enters the block Y, and they remain in such positions until the rear end of the train passes beyond the light beam. In other words, these two vehicle controlled actuators, one consisting of a photo-electric device and the other consisting of an electromagnetic device are so operated that when the front end of a train enters the block Y the detecting relay IXR. is released and. the receiving relay IZR is' picked up sequentially and they are subsequently retained at these respective positions until the entire train passes into the block Y. The location 3 and all other signal locations of my system are provided with two actuators similar to these two actuators of location I.

Each block is equipped with a registration relay designated by the reference character S plus an exponent corresponding to the location, and a release relay designated by the reference character SP plus an exponent corresponding to the location, and these relays are effective to store the registration of a train into the block until the full sequence of operation is performed registering the train out of that particular block, and then to release such stored registration. Concurrently with the deenergizing of'the detect- As will be fully deing relay IXR and the energizing of the receiving relay IZR a pickup circuit is completed for the registration relay is of the block Y, from battery terminal B, front contact 22 of relay IZR, wire 23, back contact 24 of relay IXR, wire 25, front contact 25 of a'relay II-lS to be shortly referred to, wire 21, winding of relay IS and to the C battery terminal, and the registration relay is is energized. Prior to the release of the detecting relay IXR, the relay IHS, the front contact 26 of which is interposed in the pickup circuit of the registration relay !S, was energized in a manner to subsequently appear and a stick circuit had been completed to retain it energized. This stick circuit includes the following elements, battery terminal B, front contact 28 of relay IXR, wire 29, back contact 39 of relay ES, wires 3i and 32, front contact 33 of relay iHS, wire 34, front contact 35 of a line control relay lI-ID to be later described, wire 33, winding of relay iHS and to the C battery terminal. This stick circuit was broken when relay EXR, was deenergized and hence the relay IHS was also deenergized, however, relay HHS did not immediately open its front contacts since it is slow releasing in character. Thus, the registration relay IS is picked up as described above before the front contact 26 of the relay [HS is opened.

With the registration relay 1' S once picked up it is retained energized over a stick circuit consisting of two paths, a first one of which extends from the B battery terminal over the front contact 31 of relay lI-ID, wire 38, front contact 353 of relay is, winding of that relay and thence to the C battery terminal. The second path of this stick circuit extends from the B battery terminal over the back contact 453 of a release relay 5S1, wires 4! and 38, and thence as before traced for the first path. It follows that the registration relay IS once picked up in response to a train entering the block Y it is released only when the relay !HD is deenergized and its front'contact 3! opened, and the release relay iSP is picked up and its back contact 4!] opened at the same time.

The release relay ISP for the block Y is normally deenergized as shown and may be energized by virtue of a line circuit traced from the B battery terminal at location 3 over front contact 18 of the detecting relay BXR, wire '59, front contact 80 of the registration relay 38 for the block Z, wire E25, normally closed contact I25 of a push button BPB to be later referred to, line wire 3!, winding of the relay ISP and thence to the terminal C and back over the common line wire C! to the terminal 0 of the battery at the location 3. It follows that the release relay ISP is picked up only after the registration relay 38 for the block Z has been picked up and stuck onergized in response to the head end of a train entering the block Z, and the detecting relay 3X3. has been reenergized in response to the rear end of such train passing out of the block Y and into the block Z. As set forth above, the release relay ISP when thus picked up opens at its back contact 49 one of the two parallel paths of the stick circuit for the associated registration relay IS to release that relay. Hence, the relay iSP functions to clear out the registration of a train into the block Y when a proper registration of the train into the next block Z and the registration of the rear end of the train out of the block Y are completed, it being understood, of course, that the line control relay lHD functions to open the other path of the stick circuit for the relay IS in a manner to be subsequently explained. The control of the registration and release relays of the remaining blocks of my system is similar to that explained for the relays IS and IS? of block Y.

A conventional polarized line control relay and an associated slow release repeater relay are used at each location to effect a control of a signaling device, and under certain conditions to effect a control of the registration relay. Furthermore,

the polarized line control relay of one location is front contact (if of the detecting relay 3XR, wire o 68, normally closed contact 69 of the push button 3PB, wire 78, front pole-changing contact ll of a relay 3H8, line wire l2, winding of relay II-ID, line wire 73, a second front pole-changing contact E4 of relay SEES and to the C terminal of the battery at location 3, and the reiay IHD is energized with current of a polarity which I will call normal polarity, the relay 3X5 being also picked up. It is clear that with the rciay 3H8 released and its back pole-changing contacts '25 and T8 :1

closed and the other elements of the circuit for the relay till) remaining as described, the relay iHD is energized with current of the reverse polarity, the relay 3X8 being retained picked up during such reversal of polarity since it is slow releasing in character. It is to be seen that in the case the line circuit for the relays IHD and 3X8 is opened and these relays are released, they can be reenergized only in the event a path is closed around the front contact 64 of relay 3X8. f

Such a shunt path is provided and includes a nor-, mally open front contact ll of the registration relay 38, as will be understood upon an inspection of Fig. lb.

The repeater relay [HS associated with the line control relay iHD is provided with two pickup circuits in addition to the previously traced stick circuit by which it is normally retained energized. One such pickup circuit includes the battery terminal B, front contact 28 of the detecting relay IXR, wire 29, back contact 30 of relay IS, wires 3! and 94, front contact 95 of relay lSP, wires 96 and 34, front contact 35 of relay lI-ID, wire 36, winding of relay II-IS and thence to the C battery terminal. pickup circuit is the same as the one just traced up to the wire 94 and thence over wire 91, a normally open contact 98 of a push button IPB, wire 99 to the wire 34 and thence as before traced for the first pickup circuit. The manner whereby the line control relay IHD, the repeater relay IHS and the stick relay 3X5 function will appear as the specification progresses.

As here shown, each block is equipped with two train signaling devices one of which is a wayside signal designated by the reference character G with an exponent corresponding to its location, and the other of which is a wayside inductor designated by the reference character V with an exponent corresponding to the location and which inductor is the roadside portion of an intermittent train stop system to be described hereinafter. The wayside signals G may be of any of the wellknown standard types now in general use and as here shown each is a color light signaladapt- The other 1 ed to display a clear, an approach and a stop indication. The clear signal lamp 49 for the signal IG, for example, is illuminated by virtue of an operating circuit which includes the B battery terminal, back contact 42 of the registration relay IS,-wire 43, front contact 44 of relay IHS, wire 45, front neutral contact 46 and left-hand polar contact 41 of relay IHD, wire 48, lamp 49 and to the C battery terminal. The approach signal lamp 50 of signal IG is illuminated by virtue of a circuit which is the same as just traced for the clear signal lamp 49 up to the front neutral contact 46 of relay IHD and thence over the right-hand polar contact I, wire 52, lamp and to the 0 battery terminal. The operating circuit for the stop signal lamp 53 of signal IG includes two paths the first of which extends from the B battery terminal over front contact 54 of relay IS, wire 55, lamp 53 and to the C battery terminal. The second path for the lamp 53 includes the back contact 42 of relay IS, wire 43, back contact 55 of relay I HS and thence as before traced for the first path. All other wayside signals are provided with similar operating circuits.

The operating winding 51 of the wayside inductor IV of the second signaling device at location I is normally short circuited by virtue of a circuit which may be traced from the righthand terminal of the winding 51 over wire 58, front contact 59 and left-hand polar contact 60 of relay IHD, wire 6|, front contact 62 of relay II-IS and wire 63 to the left-hand terminal of the winding 57. It follows that the winding 51 of the wayside inductor IV is short circuited under the condition that causes the signal IG to display a clear indication, but that the winding 5! is open circuited under the conditions that cause the signal IG to display either an approach or a stop indication. As will appear when the train-carried apparatus is described, the wayside inductor IV has its winding 5'? short circuited to permit a train-carried receiver RI of the vehicle K to pass over it without causing an automatic application of the vehicle brakes, and has its winding 51 on open circuit for causing an automatic application of the train brakes when the train-carried receiver RI passes over it. The wayside inductor W is preferably similar in construction to the wayside receiver IR and is located slightly in the rear of the light beam of location I. The inductor IV is mounted parallel with the track and at a distance outside of the traffic rails slightly greater than the receiver IR. Such spacing of the wayside receiver IR and wayside inductor IV permits the train-carried receiver RI to pass by the wayside receiver IR without magnetic influence, and the train-carried inductor I to pass by the wayside inductor IV without magnetic influence.

To authorize a vehicle or train to move from the siding W to the main track and to provide the clearing out of the block registration when a train moves to the siding, the following equipment is provided at the switch 3W. As shown schematically by a dotted line, a switch circuit controller of the usual type is operatively connected with the switch 3W, the adjustment being such that the contacts 82, 83, and 04 of such circuit controller are set in the position indicated by the solid lines when the switch 3W is set for main line movements and are moved to the dotted line positions when the switch is set for movements in and out of the siding. A slow release relay 3WR and a manually operate'd push'button 3W? are so aranged that at such time as the switch 3W is set for main line movements and the contact 84 is closed and the push button 3WP is depressed and its contact 85 is closed, a simple circuit easily traced is completed and the relay 3WR is energized. The relay 3WR when picked up closes at its front contact 86 a simple circuit for an indicating lamp 3PK, closes at its front contact 81 a circuit effective to energize the release relay 3SP, as will be readily understood by an inspection of Fig. 1b, and closes at its front contact 88 a circuit connection for shunting around the stick contact of the XS slow release stick relay at the next location east of the switch 3W. A switch indicator 3K is controlled over a line circuit which is carried back for a sufficient number of locations to give a desired approach indication and which line circuit includes the front contact 89 of the repeater relay 3H8, line wire 90, front contact 9| of the repeater relay IHS and line wire 92, as will be understood by an inspection of the drawings, it being further understood that the line wire 92 is connected with a B terminal of a current source at some location to the left of the 10- cation I.

The equipment of each signal location also includes a three-position manually operated push button indicated by the reference character PB with an exponent corresponding to the location r and the function of which will appear when the operation of the system is described.

Referring now to Fig. 2, the train-carried equipment includes beside the inductor I and the receiver RI shown mounted on the vehicle K of Fig. la, a control relay MS, an electropneumatic valve EP, two manually operated circuit controllers AT and ATI, a resistor M and a rectifier SA. The equipment will also include, of course, a suitable source of current and a housing for the apparatus. As here shown, the train-carried equipment is that for a well-known intermittent train stop system in present day use with the inductor I and the circuit controller ATI added.

This apparatus will be described only insofar as seems necessary for an understanding of the operation of my invention in conjunction with such train stop systems since the specific structure of such train-carried equipment forms no part of my invention and it will be understood that other forms of train stop apparatus may be used if found desirable to do so. With the train-carried apparatus in its normal position, that is, the position illustrated in Fig. 2, the principal or hold clear circuit may be traced from the positive terminal B of the train-carried current source over wire I00, contact IOI, an armature I03 and a second contact I02 of the relay MS, winding of that relay, secondary winding I06 of the receiver RI, a portion of the primary winding I05 of that receiver, winding of the magnet of the valve EP and thence over wire I05 to the negative terminal C of the current source. The primary winding I05 of the receiver RI is also energized through a branch circuit extending from the B battery terminal up to the armature I03 of relay MS, thence over a normally closed contact I01 of the manually operated circuit controller ATI, the full portion of the primary winding I05, winding of magnet valve EP and wire I05 to the C terminal of the current source. This latter branch circuit is thus in parallel with the first circuit which includes the winding of the relay MS, and the combined influences of the two currents flowing in the winding of the magnet valve EP is cffective to energize that magnet and hold the train brakes released, whereas operation of the relay armature I63 out of engagement with the contacts ISM and IE2 .to open both circuits, or the raising of the circuit controller ATI to open the contact IE3! and thereby stop the flow of current of one of the circuits, is cfiective to release magnet valve EP and cause an application oi the train brakes. It will be understood, of course, that in accordance with usual practice a delayed action of the valve EP is provided whereby magnet of the valve may be deenergized for a period of, say, four seconds before an applica tion of the train brakes is effected. The relay MS is of the type including a permanent magnet and a biasing element (not shown) whereby the armature IE3 is snapped to the right from the position shown in Fig. 2 to a position out of engagement with the contacts II?! and I92 when the winding of the relay is deenergized. The arrangement is such that when the receiver R5 passes over a wayside inductor such as the inductor IV, and the winding of the wayside inductor is short circuited, as would be the case at the entrance of a clear block, the counter-electromotive force generated in the secondary winding lad is so slight that the relay MS does not open and the vehicle may proceed Without interruption. If, however, the winding of the wayside inductor is on open circuit, as would be the case at the entrance of a block where the wayside signal indicates stop or approach, the counterelectromotive force generated in the secondary winding 5% is opposite in polarity to the energy supplied by the train-carried current source, and is sufiicient to cause the relay MS to be operated and open its own circuit as well as the circuits to the magnet valve EV with the result that a brake application is effected. The circuit for picking up or restoring the relay MS to its normal position includes a normally open contact I08 of the circuit controller AT, the circuit being as follows, terminal B, contact I08, winding of relay MS, secondary winding 5%, a portion of the primary winding I535, winding of magnet valve EP and to the C terminal of the current source. With the circuit controlled AT actuated to close the contact I08 for the picking up of the relay MS a second contact I39 is also closed to complete an energizing circuit for the primary winding Hi5 and which circuit includes the resistor M and the full portion of the primary winding I 95 as will be understood by an inspection of Fig. 2. It is to be noted that the circuits completed by the operation or" the controller AT are the usual forestalling circuits provided with the usual automatic train stop systems.

The rectifier SA is connected with a shunt path across the relay contacts, windings of the receiver RI, and winding of magnet valve EP. This rectifier SA is so positioned as to offer a high resistance to the flow of current supplied by the vehicle source but serves as a by-pass for the inductive effect created in the windings oi the vehicle apc paratus, and hence it serves as a spark arrester when the relay contacts are operated.

Operation of the circuit controller ATI from engagement with the contact IIJ'I into engagement with the contact I IE3 is effective to energize the winding ill of the train-carried inductor I, the circuit being easily traced and including the contact I6 l-I E53 of the relay MS. As here shown. the contact it??? of the controller ATI assures that the controller ATl is not permanently raised with the contact IQ'I open the elcctropneumatic valve EP is released. However, it is to be pointed out that the inductor I may be continuously energized if desired. In this latter case, the electropneumatic valve EP would be controlled over the usual circuit with the contact I! omitted.

In describing the operation of the apparatus, I will first describe a train moving east straight through the blocks X, Y and Z. Next, I will describe a train moving east into the block Z and hacking into the siding W and clearing the main line, and then I will describe a train entering the block Z from the siding W. Lastly, I will describe a movement representing a train backing into a block against the current of traflic, and the manual keying by operation for at times clearing the signaling devices to authorize a train to move into the block in advance.

Referring to Figs. la and 1b and assuming that the signal IG displays a clear indication and the vehicle K shown at the left-hand end of Fig. 1a advances toward the east, the front end of such vehicle first intercepts the light beam at location I and the detecting relay IXR is released. At this point, the operator of the vehicle operates the controller ATI to energize the traincarried inductor I with the result that as the inductor I passes over the wayside receiver IR, an electromotive force is induced in the receiver and the receiving relay I ZR is picked up. Concurrently, with the operation of the relays IXR and IZR the registration relay IS is picked up and stuck energized thus storing the registration of the vehicle into the block Y. The picking up of the registration relay IS is effective to extinguish the clear signal lamp 49 of signal IG and to illurninatc the stop signal lamp 53, and also to release the repeater relay II-IS. Just prior to the registration of the Vehicle into the block Y the winding of the wayside inductor IV was short circuited, and hence as the traincarried receiver RI passed over that inductor the train-carried relay MS was not released and the automatic train stop apparatus was unaffected as the vehicle entered the block Y. The vehicle K advances east through the block Y under the clear signal indication received at location I, and as the vehicle passes location 3 and enters the block Z the entering of the vehicle into the block Z is registered by virtue of the registration relay 35 being picked up and stuck energized in the same manner as explained for the registration relay I S, with the result that the signal 3G is set at stop and relay 31-18 is released to open circuit the winding of inductor 3V. With the releasing of the detecting relay 3XR at location 3 and the opening of its front contact til, the line circuit for the relay II-ID is opened and that relay as well as its associated stick relay 3X6 are deenergized. The releasing of the relay IHD and the opening of its front contact 31 opens one path of the stick circuit for the registration relay IS but that relay is still retained energized over the second path of its stick circuit which includes the back contact 45 of the release relay ISP since the release relay ISP remains deenergized due to the fact that the front contact I8 of the relay 3XR is now open.

When the rear of the train of which the vehicle K is the leading vehicle passes beyond the location I, whether that is before or after the head end of the train passes the location 3, the relay IXR is reenergized and the relay IZR is released since its stick circuit is now open at the back and the inductor I unnecessarilyenergized, since contact I5 of relay IXR. The registration relay IS remains energized, however, as the rear end of the train vacates the block X since the release relay SP is still down and its back contact 40 closed. The line circuit for the relay IXS at location I and is associated HD line control relay at the location next to the left of location I is now, however, supplied with current, this circuit including battery terminal B, winding of the relay IXS, front contact I I2 of relay IS, back contact H3 of relay lZR, front contact H4 of relay IXR, contact I38 of IPB, back contacts II! and H8 of relay IHS and line wires I I5 and I IS. The polarity of the current supplied to this HD relay in the rear over the line wires H5 and H6 is of reverse polarity since the repeater relay IHS is now down and its back pole-changing contacts H1 and H3 are closed. When the train advances east and the rear end of the train passes beyond-the location 3, the relay 3XR is reenergized and the relay SZR is released. Since the front contact 853 of the registration relay 38 is now closed, the closing of the front contact 18 of the relay 3XR completes the line circuit for the release relay lSP and that relay is picked up to open at its back contact 40 the second path of the stick circuit for the registration relay IS and thus registration relay IS is released to clear out the registration at location I. It is to be noted that the release of the relay 3ZR is retarded due to the snubbing action of the rectifier 3RX which is connected across its operating winding and thus shunting the current induced by the collapse of the flux in its magnetic structure. This retardation of the release of relay 32B is of suflicient duration to hold the circuit for the line control relay IHD open at back contact 66 long enough after the relay 3XR is reenergized to permit the energization of the release relay ISP and the subsequent deenergization of the registration relay IS, which is a quick release relay, before the relay IHD is picked up and closes at its front contact 31 the first path of the stick circuit for the relay IS. With the release relay ISP picked up and its front contact 95 closed and the relay IS released and its back contact 30 closed, the energizing of therelay IHD to close its front contact 35 completes the pickup circuit for the repeater relay IHS since the relay IXR is now energized and its front contact 28 is closed. With the picking up of the relay II-IS and the closing of its front contact 44 the operating circuit for the lamp 50 is completed and signal IG displays an approach indication since the relay IHD is now energized by current of reverse polarity and its right-hand polar contact 5| is closed. It is to be seen, therefore, that the clearing out of the registration at location i and the displaying of an approach indication by the signal 1G takes place only after the train has been registered into the block Z, the signal 3G set at stop, the inductor 3V open circuited, and the rear end of the train has been registered out of the block Y by restoring relays SXR and 3ZR to their normal position. When the train has advanced east out of the block Z and the repeater relay BHS has been reenergized in a manner similar to that explained for reenergizing the repeater relay IHS, the current supplied to the relay IHD at location I is then of normal polarity and the indication of the signal IG is changed from approach to a clear indication.

I will now assume that the vehicle K starts from its position in Fig. la and advances east and is registered into the block Z in the manner explained above, and has stopped at the switch 3W preparing to back into the siding W. Underthis condition, relay SS is energized, relay 3H8 is deenergized, relay 31-113 is energized, assuming, of course, that the front end of the vehicle K has not advanced east of the next location to the right of location 3, and the release relay 3S? is deenergized. Also, the relays 3X8, 3ZR and 3XR at location 3 are now in the position shown. When the switch 3W is thrown to its reverse position to permit the train to back into the siding W, the circuit for the relay 3HD is opened at the contacts 32 and 83 and that relay is released and by virtue of its associated XS stick relay at the next location to the east the line circuit for the relay SHD is stuck open. As previously pointed out, in order to register a train out of a block the HD relay must be deenergized and the SP release relay energized to release the S registration relay; and then the HD relay must be reenergized while the SP relay is still energized to permit the HS repeater relay to become energized and clear the wayside signal. Since the train at switch 3W did not register out of the exit end of the block Z, the release relay 3SP is deenergized and therefore the apparatus at the switch location must be effective to energize that relay as well as to deenergize and then reenergize line relay 3HD in order to register the train out of the block. This is accomplished by having a trainman depress the push button 3WP (which is placed under lock or may be in the form of a switch key circuit controller). The depressing of the push button 3WP after the switch 3W has been restored to its normal position causes the relay SWR to be picked up and, since it is slow i releasing in character, it does not open its front contact for several seconds after the push button 3WP is restored to its normal position. It is to be noted that the line control circuit for the relay 3I-ID is carried over the normally closed contacts H9 and I20 of the push button 3WP to check that the push button is restored to its normal position before the signal 3G can clear. Concurrently, with the energization of the relay 3WR and the closing of its front contact 81, current is fed to the release relay 3SP and that relay is picked up. Since the relay 3HD is now deenergized both paths of the stick circuit for the registration relay 38 are open and that relay is released, and the registration stored at the location 3 is cleared out. While the relay SWR is energized and its front contact 38 is closed a path is completed around the stick contact of the XS relay at the next location to the right permitting thereby that relay and the relay 3HD to become reenergized. When the relay 3I-ID is thus reenergized and its front contact I28 is closed, the repeater relay 3H8 becomes energized since the release relay 3SP is now picked up and its front contact l2| is closed, this circuit also including contact 78 of relay 3X12, and back contact I29 of relay 3S. At the end of the slow release period of the relay 3WR that relay is released and hence the release relay 3SP is again deenergized. Consequently, the apparatus for block Z is restored to its normal position by the manipulation of the push button 3WP following the closing of the switch 3W. It is to be noted that with the energization of the relay SWR and the closing of its front contact 86 the indicator lamp 3PK is lighted to indicate to the trainman that the relay SWR is picked up.

I will now describe how a vehicle or train is registered into the block Z from the siding W. When the switch 3W is operated to its reverse may actually have entered the up and is stuck energized over the path of its stick circuit which includes the back contact me of the release relay 38F. The signal 3G is set to display a stop indication in response to the energizing of the registration relay 3S and, consequently, registration of the vehicle into block Z is accomplished by the operation of the switch only. Authorization to open the switch is obtained by the switch indicator 3K, the control of which, as stated hereinbefore, is carried to the rear for a sufficient number of signal locations to give a desired approach indication.

A move against the current of trafiic into the block previously vacated cannot with safety be made except under flag protection, so I have provided for such operation when movement against the current of trams is contemplated. Assuming the vehicle K is registered into the block Z and out of the block Y in the manner previously described, the signal IG is permitted to display an approach indication authorizing a following vehicle to advance east past the location i. Therefore, if the vehicle K in block Z is to be permitted to again enter the block Y from the right, a flagman is sent out to protect the movement. At the location 3 the flagman sets the push button 3P3 at its center position where all contacts operated thereby are open. Since the line circuit for the relay IHD includes the contact 58 of the push button 3P8 that relay is deenergized and in turn its repeater relay lI-IS is released and the signal IG is set to indicate stop, the operating circuit for the stop lamp 53 of the signal IG being closed at the back contact 62 of relay IS and the back contact 56 of relay IHS. Since a following train lock Y registering into that block while relay lSP is energized, it is not desirable to permit relay is to become deenergized in response to the flagman operating the push button 3PB and releasing both relays ISP and EHD, therefore, relay lSP must be released before the relay !HD is released. This is accomplished by the contact 69 of the push button 3PB being adjusted to break its contact an instant after the contact !28 is opened. With the push button SPB thus operated the vehicle in the block Z may back into the block Y under protection of the flagman, the open contact I26 preventing a false registration out of the block Y in the event a registration is stored at the location I. When the vehicle which has backed intothe block Y in the manner just explained, is ready to advance east again out of the block Y, the push button 3P3 must be placed back at its normal position.

To key-by a stop signal when a train comes up to such stop signal, say the signal K for example, the trainman may depress the push button IPB to its full down position and close the contact 98. If the block Y is not occupied by another train and the registration relay is is deenergized, the repeater relay lHS is supplied witcurrent over its pick-up circuit including the contact 98 and that relay is picked up to permit the clearing of the signal IG. Should the signal fail to clear due to th relay lHD being open for whatever cause, the train must wait for 2. proceed indication or advance under proper orders and with proper flag protection.

Although I have herein shown and described only one form of apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

l. A signaling system comprising in combination with a trackway and a vehicle adapted to travel on the trackway, a plurality of electroresponsive registration means one at each of a plurality of spaced locations along the trackway and each normally deenergiaed, circuit means at each location for energizing the registration means and normally ineffective, vehicle actuated means at each location operative to render said 12.

circuit means effective only during the interval a vehicle passes the location, storage means at each location eiiective to retain the registration means energized, release means at each location controlled by the vehicle actuated means at the location next in advance and operative to deenergize the associated registration means in response to the vehicle passing such location next in advance, and vehicle signaling means controlled by the registration means.

2. A signaling system comprising in combination with a trackway and a vehicle adapted to travel on the trackway, a plurality of electroresponsive registration means one at each of a plurality of spaced locations along the trackway, r)

an intermittent control means at each location for energizing the registration means and includ-- ing a vehicle controlled actuator operative to render such control means effective when and only when a vehicle is passing the location, storage means at each location effective to: retain the registration means energized, release means at each location controlled by the vehicle controlled actuator at a location in advance and operative to deenergize the associated registration means in response to the vehicle passing such location in advance, and vehicle signalingmeans controlled by the registration means.

3. A signaling system comprising in combination with a trackway and a vehicle adapted to travel on the trackway, a plurality of electroresponsive registration means one at each of a plurality of spaced locations along the trackway, an intermittent control means at each location for energizing the registration means and operative to deenergize the associated registra-- tion means when and only when the entire vehicle has passed such location in advance, and vehicle signaling means controlled by the registration means.

l. A signaling system comprising in. cornbination with a trackway and a vehicle adapted to travel on the trackway, a. plurality of electroresponsive registration means one at each of a plurality of spaced locations along the trackway, a vehicle controlled actuator at each location operated to one position when the front end of the leading vehicle of a train of several vehicles passes the location and subsequently operated to a second position when the last vehicle of said train passes beyond the locations, a pickup circuit at each location for energizing the registration means and including a contact closed in said one positionof the actuator, a stick circuit at each location effective to retain the registration means energized, a release circuit for each location to deenergize the registration means and including a contact of the actuator at the location in advance and closed when such actuator in advance is operated to said second position, and vehicle signaling means controlled by each registration means.

5. A signaling system comprising in combination with a trackway and a vehicle adapted to travel on the trackway, a plurality of electroresponsive registration means one at each of a plurality of spaced locations along the trackway, an intermittent control means at each location for energizing the registration means and including a light sensitive element operative to render the control means effective to energize the registration means when the front end of the leading vehicle of a train of several vehicles passes the location and subsequently retains it efifective until the rear end of the last vehicle of the train passes beyond the location, storage means at each location efiective to retain the registration means energized, release means at each location controlled by the light sensitive element at a location in advance and operative to deenergize the associated registration means when and only when the last vehicle of the train has passed such location in advance, and vehicle signaling means controlled by the registration means.

6. A signaling system comprising in combination with a trackway and a vehicle adapted to travel on the trackway, a plurality of electroresponsive registration means one at each of a plurality of spaced locations along the trackway, a vehicle actuated means at each location having a normal position and adapted to be moved to an operated position when and only when some portion of a vehicle occupies the location, means governed by the vehicle actuated means in the operated position for energizing the associated registration means, storage means at each location efiective to retain the registration means energized, release means at each location controlled jointly by the vehicle actuated means and the registration means at a location in advance and operative to deenergize the associated registration means in response to the registration means in advance energized and the vehicle actuated means in its normal position, and signaling means controlled by each registration means.

7. A signaling system comprising in combination with a trackway and a'vehicleadapted to travel on the trackway, a plurality of registration relays one at each of a plurality of spaced locations along the trackway, a vehicle actuated means at each location having a normal position and adapted to be moved to an operated position when and only when some portion of a vehicle occupies the location, a pickup circuit for each registration relay and including a contact closed only in the operated position of the associated vehicle actuated means, a release relay at each location and normally deenergized, a stick circuit for each registration relay and including a back contact of the associated release relay, a line circuit for energizing each release relay and ineluding a front contact of the registration relay at a location in advance and a contact closed only in the normal position of the vehicle actu ated means at such location in advance, a signaling device at each location, and operating circuits for each signaling device selectively controlled by the associated registration relay.

8. A signaling system comprising in combination with a trackway and a vehicle adapted to travel on the trackway, a plurality of registration relays one at each of a plurality of spaced locations along the trackway, a vehicle actuated means at each location having a normal position and adapted to be moved to an operated position when and only when some portion of a vehicle occupies the location, a pick-up circuit for each registration relay and including a contact closed only in the operated position of the associated vehicle actuated means, two stick circuits for each registration relay each effective to retain the registration relay energized, a first release means controlled by the vehicle actuated means at the location next in advance effective to open one of the stick circuits when said actuated means at the point in advance is moved to its operated position, a second release means controlled jointly by the registration relay and the vehicle actuated means at the location next in advance and effective to open the other stick circuit when said registration relay is energized and the vehicle actuated means is restored to its normal position, and signaling means controlled by each registration relay.

9. A signaling system comprising in combination with a trackway and a vehicle adapted to travel on the trackway, signaling means one at each of a plurality of spaced locations along the trackway, a registration relay at each location effective when energized to set the signaling means at the same location at stop but normally deenergized, a vehicle actuated means at each location having a normal position and adapted to be moved to an operated position when the front end of a vehicle passes the location and subsequently held in that position until the rear end of the train passes beyond the location, control means governed by the vehicle actuated means when operated for energizing the registration relay, a stick circuit at each location efiective to retain the registration relay energized, and release means at each location controlled jointly by the registration relay and the vehicle actuated means at the location next in advance and effective to open said stick circuit when and only when the vehicle actuated means at the location in advance is operated and the registration relay at that location is energized and the vehicle actuated means is subsequently returned to its normal position.

10. A signaling system comprising in combination with a trackway and a vehicle adapted to travel on the trackway, signaling devices one located at each of a plurality of spaced locations along the trackway, photo-electric means at each location including a light sensitive element responsive to any portion of a vehicle occupying the location, electro-magnetic means at each location including a trackway magnetic receiver responsive to the influence of a vehicle-carried inductor as a vehicle passes the location, and means controlled jointly by the light sensitive element and the magnetic receiver of each location for governing the signaling device.

11. A signaling system comprising in combination with a trackway and a vehicle adapted to travel on the trackway, signaling devices one located at each of a plurality of spaced locations along the trackway, a first contact at each location, means at each location for operating said first contact when the front end of a vehicle passes the location and for subsequently maintaining said contact in its operated position until the rear end of the vehicle passes beyond the location, a second contact at each location, trackway means at each location responsive to the influence of a vehicle-carried means effective to opcrate said second contact when the vehicle-carried means passes the trackway means of the same location, and means controlled jointly by the two contacts of a location when operated for governing the signaling device of the same location.

12. A signaling system comprising in combination with a trackway and a vehicle adapted to travel on thetrackway, signaling devices one located at each of a plurality of spaced locations along the trackway, a first electroresponsive means at each location including a light beam transverse to the trackway and a contact operated when the front end of the leading vehicle of a train of several vehicles intercepts the light beam and subsequently remains operated until the rear end of the last vehicle of such train passes beyond the light beam, a second electroresponsive means at each location including a trackway magnetic receiver responsive to the influence of a vehicle-carried inductor and a contact operated when a vehicle-carried inductor passes over the trackway receiver, and means at each location controlled jointly by said two contacts of the same location and effective to operate the signaling device of the same location and the signaling device at a location in the rear in response to said operation of the contacts.

13. A signaling system comprising in combination with a trackway and a vehicle adapted to travel on the trackway, a first electroresponsive means including a light beam transverse to the trackway and a contact operated when the front end of the leading vehicle of a train of several vehicles intercepts the light beam and subsequently remains operated until the rear end of the last vehicle of such train passes beyond the light beam, a second electroresponsive means including a trackway magnetic receiver responsive to the influence of a vehicle-carried inductor and a contact operated when such vehicle-carried inductor passes over the trackway receiver, and a signaling device controlled jointly by said two contacts.

14. A signaling system comprising in combination with a trackway and a vehicle adapted to travel on the trackway, a first electroresponsive means including a light beam transverse to the trackway and a contact operated when the front end of the leading vehicle of a train of several vehicles intercepts the light beam and subsequently remains operated until the rear end of the last vehicle of such train passes beyond the light beam, a second electroresponsive means including a trackway magnetic receiver responsive to the influence of a vehicle-carried inductor and a contact operated when such vehicle-carried inductor passes over the trackway receiver, and a signaling device controlled jointly by said two contacts and operated when and only when both contacts are operated at the same time.

15. A signaling system comprising in combination with a trackway and a vehicle adapted to travel on the trackway, photo-electric means including a light beam disposed along the trackway for-interception by a vehicle passing along the trackway and a contact operated when the front end of a vehicle intercepts the light beam and subsequently remains operated until'the rear end of the vehicle passes beyond the light beam, electromagnetic means including a receiver disposed along the trackway for inductively receiv ing an electromotive force from a vehicle-carried inductor and a contact operated by such electromotive force in response to a vehicle passing the receiver, and a signaling device controlled jointly by said two contacts.

16. A signaling system comprising in combination with a trackway and a vehicle adapted to travel on the trackway, photo-electric means including a light beam disposed along the trackway for interception by a vehicle passing along the trackway, electromagnetic means including a receiver disposed along the trackway for inductively receiving an electromotive force from a vehicle-carried inductor, and a vehicle signaling device controlled jointly by said photo-electric means and said electromagnetic means.

1'7. A signaling system comprising in combination with a trackway and a vehicle adapted to travel on the trackway, photo-electric means including a light beam disposed along the trackway and a detecting relay operated to a given position when the front ent of a vehicle intercepts the light beam, electromagnetic means including a receiver disposed along the trackway for inductively receiving an electromotive force for a vehicle-carried inductor and a receiving relay energized by such electromotive force in response to a vehicle passing the receiver, and a signaling circuit including in series a contact of the detecting relay closed in said given position and a front contact of the receiving relay.

18. A railway signaling system comprising a stretch of railway track, a plurality of signaling devices one located at each of a plurality of spaced locations along the track, a trafiic responsive device at each location, a line relay and a stick relay at each location; a line circuit controlled by each trafiic responsive device and including the winding of the stick relay at the location of said device, a front contact of such stick relay and the winding of the line relay for the location next in the rear in series whereby said line circuit once opened is stuck open; means controlled by the trafiic responsive device for at times closing a shunt path around the stick contact, and means controlled by each line relay for governing the signaling device at the same location.

19. A railway signaling system comprising, a stretch of railway track including a track switch, a signal located adjacent the entrance of said stretch for governing traffic therethrough, a registration relay effective when energized to set the signal at stop but normally deenergized, train actuated means disposed adjacent the entrance of the stretch operative to energize said registration relay in response to a train entering the stretch, a stick circuit effective to subsequently retain said relay energized, a first controller operatively connected with said. switch, a manually operable circuit controller located adjacent the switch, and means controlled jointly by said two circuit controllers for at times opening said stick circuit to release said relay.

20. A railway signaling system comprising a stretch of railway track including a track switch, a signal located adjacent the entrance of said stretch for governing traffic therethrough, a

registration relay effective when energized to set contact of said train actuated means and closed the signal at stop but normally deenergized, train in said given position, a second pickup circuit for actuated means disposed adjacent the entrance said relay including a contact of said circuit con- 01 the stretch and actuated to a given position in troller and closed when said track switch is response to a train entering the stretch, a circuit open, and a stick circuit efiective to subsequently 5 controller operatively connected with said switch, retain said relay energized.

a first pickup circuit for said relay including a RALPH R. KEMMERER. 

